Integration in R language

I'm trying to compute the integral between 1 and some cutoff 'cut' of the function given in the R-code below as 'int'. It depends on 2 parameters dM[i] and dLambda[j] defined before I make the integration and for each pair I save the results in vector 'vec':

vec = c() #vector for INT values: this is our goal
dM = seq(from = 0, to = 3, by = 0.01) #vector for mass density parameter
dLambda = seq(from = -1.5, to = 3, by = 0.01) #vector for vacuum energy density parameter

for (i in 1:length(dM)) {
  for (j in 1:length(dLambda)) {

    int = function(x) ((dM[i]*x^4*(x - 1) + dLambda[j]*x^2*(1 - x^2) + x^4)^(-1/2))
    cut = 30
    INT_data = integrate(int, 1, cut)
    INT = INT_data$value
    vec = c(vec, INT)
  }
}

But when I run the script I get the error: "Error in integrate(int, 1, cut) : non-finite function value ". Nonetheless, if I tried the following code

int = function(x) ((0*x^4*(x - 1) -1.5*x^2*(1 - x^2) + x^4)^(-1/2))
cut = 30
INT_data = integrate(int, 1, cut)
INT = INT_data$value
vec = c(vec, INT)

I get the correct result without any error. So the error above is not true, it can calculate the integral but it seems that R cannot work it out if I use the 2 'for'-loops. How can I re-write the code so I can compute all the different values for dM[i] and dLambda[j] I want?